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S Huck

Publications and source records attributed to S Huck.

68 records · Page 4Linked to original sources
PubMed1984

Gliotoxic effects of alpha-aminoadipic acid on monolayer cultures of dissociated postnatal mouse cerebellum.

The cytotoxic effects of DL-, D- and L-alpha-aminoadipic acid, a six-carbon homologue of glutamate, were investigated in cell cultures of dissociated postnatal mouse cerebellum. Treatment with alpha-aminoadipic acid resulted in rapid nuclear and cytoplasmic swelling and, after longer periods of exposure, karyopyknosis of astrocytes, identified by indirect immunofluorescence labelling with anti-human glial fibrillary acidic protein antiserum. The number of astrocytes with pyknotic nuclei depended on the concentration of alpha-aminoadipic acid as well as on the duration of drug action. The presence of 0.21 mM DL-alpha-aminoadipic acid or 0.10 mM L-alpha-aminoadipic acid for 40 h caused karyopyknosis in 50% of the astrocytes. In contrast, D-alpha-aminoadipic acid, had little gliotoxic activity. None of the cytotoxic effects of DL-alpha-aminoadipic acid or L-alpha-aminoadipic acid observed for astrocytes were seen for the neurons present in the cultures when the drug was added after 4 days in vitro. Neurotoxic effects were evident, however, when alpha-aminoadipic acid was included in the culture medium at plating. These results indicate that alpha-adminoadpic acid can be used to substantially reduce the number of astroglia in cerebellar cultures and that dissociated cell cultures will provide a useful model with which to study the mechanisms of alpha-aminoadipic acid induced glial toxicity.

2-Aminoadipic Acid↗
PubMed1984

The glutamate analogue alpha-aminoadipic acid is taken up by astrocytes before exerting its gliotoxic effect in vitro.

DL- and L-alpha-aminoadipic acid (alpha-AA) are specific gliotoxins in vitro (Huck, S., F. Grass, and M. E. Hatten (1984) Neuroscience 12: 783-796). By combining immunohistochemical and autoradiographic techniques, we now show that DL-[14C]-alpha-AA is accumulated almost selectively by astrocytes in cultures of the dissociated postnatal mouse cerebellum, presumptive neurons being free of the radiolabel. High pressure liquid chromatography analysis of cultures incubated with D- or L-alpha-AA and DL-[14C]-alpha-AA autoradiograms conducted in the presence of D- or L-alpha-AA reveal a stereospecificity of astroglial L-alpha-AA uptake. Both the uptake of alpha-AA by astrocytes and alpha-AA-induced gliotoxicity were sodium dependent. Since 2 microM tetrodotoxin did not prevent the morphological changes, we conclude that sodium plays its role in alpha-AA-induced gliotoxicity by mediating the transport of the substance. Thus, alpha-AA appears to be taken up by the astrocytes before exerting its cytotoxic effect.

2-Aminoadipic Acid↗
PubMed1983

Serum-free medium for cultures of the postnatal mouse cerebellum: only insulin is essential.

Serum-free culture conditions for dissociated postnatal mouse cerebellar cells were investigated. This study demonstrates that among various supposed growth-promoting factors only insulin is required as an additive to the basic medium. If viewed by phase contrast microscopy, cultures kept in insulin-supplemented basic medium looked identical to those maintained in the presence of a mixture of growth-promoting factors (insulin, putrescine, transferrin, progesterone, triiodothyronine, selenium). In addition, quantitative evidence is provided indicating that cellular survival is supported to the same extent by insulin as by this admixture. Insulin concentrations required ranged between 0.3-20 micrograms/ml. By contrast to serum-supplemented culture conditions, no significant proliferation of non-neuronal cells was observed in serum-free culture media. It is expected that by these findings attention will be focused again to the exact role insulin plays in the central nervous system.

Animals↗
PubMed1981

Rhythmic activity in the cerebellum and spinal cord of rabbits receiving tetanus toxin intravenously.

1. In rabbits intravenously injected with tetanus toxin (2 x 10(5) mouse LD50), a rhythmic electrical activity was recorded in the cerebellum and in the spinal cord. 2. The motor system appears to be strongly involved in this event, since the ventral roots displayed rhythmic activity correlated to the spinal cord rhythm. Extracellular recordings showed the same rhythmic discharge pattern in many alpha- and gamma-motoneurons and Renshaw cells of hindlimb flexor and extensor muscles. 3. Upon high spinalization at C1, the rhythm could be recorded in the cerebellum but no longer in the spinal cord. Cooling of the cerebellar surface suppressed the rhythm in both structures. 4. The data are discussed under the current view, that generalized tetanus is a special form of local tetanus. 5. We suggest that the rhythmic activity is of supraspinal origin and is transmitted to alpha- and gamma-motoneurons of both the flexor and extensor motor systems.

Anesthesia↗
PubMed1981

Developmental stage-specific changes in lectin binding to mouse cerebellar cells in vitro.

Eleven fluorescein isothiocyanate-conjugated (FITC) lectins, each with distinct carbohydrate-binding properties, were used to assess cell surface glycoconjugates of embryonic and early postnatal cerebellar cells in vitro. Fluorescence staining of embryonic day 13 (E13) cerebellar cells with FITC Ricinus communis agglutinin diminished markedly between 24 and 72 hr in vitro. No staining of postnatal day 0 (P0) or postnatal day 7 (P7) cells was observed with FITC Ricinus communis agglutinin. A similar, but less pronounced decrease in FITC concanavalin A, FITC Lens culinaris, and FITC wheat germ agglutinin was observed between embryonic day 13 and birth. No specific staining of E13, P0, or P7 cultures was observed with FITC peanut agglutinin, FITC Dolichos bifloris agglutinin, FITC soybean agglutinin, FITC Wistaria floribundis agglutinin, FITC Phaseolus vulgaris agglutinin, FITC Limulus polyphemus agglutinin, or FITC Ulex europaeusI agglutinin. Similar results were obtained with 125I-lectin binding assays. Ricinus communis 125-I-agglutinin binding decreased dramatically between embryonic day 13 and birth. Less pronounced decreases were observed in 125I-concanavalin A and wheat germ 125I-agglutinin binding. Very low levels of soybean 125I-agglutinin or Ulex europaeusI 125I-agglutinin were bound by either embryonic or early postnatal cerebellar cells in vitro.

Aging↗
PubMed1979

The estimation of the survival rate of tetanus-intoxicated mice. A model for screening anti-tetanus drugs.

The estimation of the survival rate of tetanus-intoxicated mice is suggested to be a useful animal model for assaying the anti-tetanus potency of drugs. This model was tested with the four central depressants phenobarbitone, chlorpromazine, diazepam and halothane. In agreement with their clinical value, diazepam appeared to be the most, phenobarbitone the least effective agent.

Animals↗
PubMed1979

[Interactions between nitrous oxide and central depressants].

The combined effects on mice of N2O and various central depressants were investigated. A loss of the righting reflex was taken as the criterion for the drug effects. Essential differences could be demonstrated in the type of interaction: diazepam, flunitrazepam, and medazepam have a supra-additive effect in combination with N2O; the solvent of diazepam and an experimental product, Ro 21-3981 (8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo [1,5-a] [1,4]-benzodiazepine maleate) a simply additive one. However, the interactions between N2O and barbiturates (pentobarbitone and phenobarbitone), and N2O and ethanol were found to be infra-additive. The results of this and previous investigations indicate that additive or supra-additive interactions can only be expected in those cases in which at most one of the two active ingredients in addition to its depressive effect also exhibits an excitatory component.

Animals↗
PubMed1976

[Effect of combined application of halothane and some central depressants (author's transl)].

The combined effects of halothane and various central depressants were studied in mice by means of an isobolographic method which allows the statistical evaluation of interactions. A loss of the righting reflex for at least 2 min was taken as the criterion for the synchronisation of the peak time of drug effects. All interactions turned out to be supra-additive, more pronounced in the case of diazepam and flunitrazepam than in the case of medazepam, pentobarbitone or ethanol. The organic solvent used for the solution of diazepam and flunitrazepam was found to contribute to the observed interactions. The difficulties of estimating and classifying combined drug effects as well as their clinical relevance are discussed.

Anesthesia, Inhalation↗
PubMed1976

Neurotoxicity and CSF level of three penicillins.

The electrocortical activity and the antibiotic concentration in serum and CSF were investigated in rabbits after i.v. administration of benzylpenicillin, ampicillin and oxacillin. In contrast to ampicillin and oxacillin, benzylpenicillin induced a pronounced epileptogenic activity. The different epileptogenic activity of the three penicillins cannot be explained by the difference in the CSF level of these agents only. The intensity of the epileptogenic activity and the CSF level after benzylpenicillin administration were markedly influenced by the experimental procedure in that curarized animals exhibited both higher CSF levels and more intense seizure activities than non-curarized animals. Factors are discussed which may be responsible for the different neurotoxic potency of the three penicillins and for the dependence of the benzylpenicillin-induced seizure intensity on the experimental procedure.

Ampicillin↗
PubMed1975

[Action of central depressants on the nitrous oxide anesthesia (author's transl)].

The synergistic action of seven central depressants three benzodiazepines, two neuroleptics on barbiturate and morphine on the anesthetic activity of nitrous oxide was studied in mice. The benzodiazipines and among them nitrazepam and flunitrazepam were found to be the most potent drugs in this respect; morphine on the other hand was innefective even in toxic doses. There was a significant difference in the slope of log dose-response curves; these curves were much steeper for pentobarbitone, droperidol and chlorpromazine than for nitrazepam, flunitrazepam, and diazepam. The theoretical and practical implications of this difference are discussed.

Anesthesia, Inhalation↗
PubMed1975

Action of six commonly used benzodiazepines on isolated guinea-pig ileum preparation.

The spasmolytic activity of six commonly used benzodiazepines was investigated on isolated guinea-pig ileum preparation. All six substances proved to be non-competitive antagonists of carbachol and barium chloride, the pD'2 values ranging between 3.23 and 4.37 in the presence of either agonist. The significance of these findings is discussed.

Animals↗